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Wang J, Appidi MR, Burdick LH, Abraham PE, Hettich RL, Pelletier DA, Doktycz MJ. Formation of a constructed microbial community in a nutrient-rich environment indicates bacterial interspecific competition. mSystems 2024; 9:e0000624. [PMID: 38470038 PMCID: PMC11019790 DOI: 10.1128/msystems.00006-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/14/2024] [Indexed: 03/13/2024] Open
Abstract
Understanding the organizational principles of microbial communities is essential for interpreting ecosystem stability. Previous studies have investigated the formation of bacterial communities under nutrient-poor conditions or obligate relationships to observe cooperative interactions among different species. How microorganisms form stabilized communities in nutrient-rich environments, without obligate metabolic interdependency for growth, is still not fully disclosed. In this study, three bacterial strains isolated from the Populus deltoides rhizosphere were co-cultured in complex medium, and their growth behavior was tracked. These strains co-exist in mixed culture over serial transfer for multiple growth-dilution cycles. Competition is proposed as an emergent interaction relationship among the three bacteria based on their significantly decreased growth levels. The effects of different initial inoculum ratios, up to three orders of magnitude, on community structure were investigated, and the final compositions of the mixed communities with various starting composition indicate that community structure is not dependent on the initial inoculum ratio. Furthermore, the competitive relationships within the community were not altered by different initial inoculum ratios. The community structure was simulated by generalized Lotka-Volterra and dynamic flux balance analysis to provide mechanistic predictions into emergence of community structure under a nutrient-rich environment. Metaproteomic analyses provide support for the metabolite exchanges predicted by computational modeling and for highly altered physiologies when microbes are grown in co-culture. These findings broaden our understanding of bacterial community dynamics and metabolic diversity in higher-order interactions and could be significant in the management of rhizospheric bacterial communities. IMPORTANCE Bacteria naturally co-exist in multispecies consortia, and the ability to engineer such systems can be useful in biotechnology. Despite this, few studies have been performed to understand how bacteria form a stable community and interact with each other under nutrient-rich conditions. In this study, we investigated the effects of initial inoculum ratios on bacterial community structure using a complex medium and found that the initial inoculum ratio has no significant impact on resultant community structure or on interaction patterns between community members. The microbial population profiles were simulated using computational tools in order to understand intermicrobial relationships and to identify potential metabolic exchanges that occur during stabilization of the bacterial community. Studying microbial community assembly processes is essential for understanding fundamental ecological principles in microbial ecosystems and can be critical in predicting microbial community structure and function.
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Affiliation(s)
- Jia Wang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Manasa R. Appidi
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, USA
| | - Leah H. Burdick
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Paul E. Abraham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Robert L. Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dale A. Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Mitchel J. Doktycz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Monitoring Bacterial Community Dynamics in Abalone (Haliotis discus hannai) and the Correlations Associated with Aquatic Diseases. WATER 2022. [DOI: 10.3390/w14111769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bacteria are an integral component of their host. However, information about the microbiota living in and around many aquatic animals is lacking. In this study, multiplex bar-coded pyrosequencing of the 16S ribosomal RNA gene was used to monitor the dynamics of abalone, Haliotis discus hannai, bacterial communities in the intestine, water from cement culture ponds, and surrounding sea areas. Correlations between the bacterial communities and common aquaculture diseases were also evaluated. A total of 329,798 valid sequences and 15,277 operational taxonomic units (OTUs) from 32 samples were obtained by 454 tag amplicon pyrosequencing. The Shannon indices of the seawater samples ranged from 2.84 to 5.6 and the Shannon indices of the abalone intestine samples ranged from 1.2 to 5.12, which were much lower than those of seawater. The dominant phyla in seawater samples were Proteobacteria, Bacteroidetes, Fusobacteria, Cyanobacteria, etc. The dominant phyla in the abalone intestine varied greatly in different months. The dominant genera in the seawater of the cement culture ponds changed in different months, mainly Psychrilyobacter and Pseudoalteromonas. The dominant genera in seawater from the open sea vary considerably between months. The dominant genus of bacteria in the abalone intestine during the months when abalones are susceptible to disease is mainly Mycoplasma spp. Canonical correspondence analysis revealed that bacterial communities in seawater and the intestine responded differently to environmental variables, with similar microbiota in the same area. pH, dissolved oxygen concentration, and temperature were closely related to the samples from the sea area. Oxidation-reduction potential, salinity, phosphate, nitrate, and ammonia nitrogen concentrations were closely related to the water samples from the artificial pools. These findings may add significantly to our understanding of the complex interactions between microbiota and environmental variables in the abalone intestine as well as in the surrounding seawater.
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Changes in Bacterial and Chemical Components and Growth Prediction for Lactobacillus sakei during Kimoto-Style Fermentation Starter Preparation in Sake Brewing: a Comprehensive Analysis. Appl Environ Microbiol 2021; 87:AEM.02546-20. [PMID: 33452026 DOI: 10.1128/aem.02546-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/27/2020] [Indexed: 11/20/2022] Open
Abstract
Kimoto-style seed mash is a traditional preparation method for sake that takes advantage of spontaneous lactic acid fermentation before the growth of yeast. Lactic acid helps decrease the pH in seed mash and control the growth of unfavorable microorganisms. In this study, we carried out a comprehensive analysis of the change in the bacterial community and chemical composition during the lactic acid fermentation stage in kimoto-style seed mash preparation. The bacterial transitions were diverse at five sake breweries, but they exhibited three patterns. Lactobacillus sakei was the dominant species in the later stage of lactic acid fermentation in all sake breweries. This species was found to be the most important bacterium for the accumulation of lactic acid, because its average production rate of lactic acid in seed mash reached 4.44 × 10-11 mg cell-1 h-1, which is 10 times higher than those of other species. As a result of specific growth rate analysis, it was revealed that the growth rate of L. sakei was influenced by the strain, pH, and temperature. The effects of pH and temperature were explained by the square root model, and the result indicates that the strains isolated in this study were incapable of growth below pH 3.9. The growth curve predicted using the growth model fit the actual cell density in two out of five sake breweries; however, our model did not work well for the remaining three sake breweries, and we presume that the error was caused by the strain or an unknown factor.IMPORTANCE It is important to produce lactic acid in kimoto-style seed mash; however, the bacterial transition is different depending on the sake brewery. The reason why there are diverse bacterial transitions during kimoto-style seed mash preparation for each sake brewery is unclear so far, and it causes difficulty in starting kimoto-style seed mash. Our findings indicate that the changes in pH caused by lactic acid bacteria grown prior to L. sakei in seed mash influence the growth of L. sakei and are related to the diversity of the bacterial transition. This study uses comprehensive analytical methods to reveal that there is a diversity of bacterial transition and chemical compositions in kimoto-style seed mash depending on the sake brewery and to explain the differences in bacterial transition depending on the characteristics of L. sakei.
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Anderson HE, Santos IC, Hildenbrand ZL, Schug KA. A review of the analytical methods used for beer ingredient and finished product analysis and quality control. Anal Chim Acta 2019; 1085:1-20. [PMID: 31522723 DOI: 10.1016/j.aca.2019.07.061] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 07/28/2019] [Accepted: 07/29/2019] [Indexed: 12/30/2022]
Abstract
Beer is an incredibly complex beverage containing more than 3000 different compounds, including carbohydrates, proteins, ions, microbes, organic acids, and polyphenols, among others. Beer becomes even more complex during storage, for over time it may undergo chemical changes that negatively affect the flavor, aroma, and appearance. Thus, it can be expected that maintaining the quality of beer throughout its lifetime is a difficult task. Since it is such a popular drink throughout the world, being familiar with proper analytical techniques for beer evaluation is useful for researchers and brewers. These techniques include, but are not limited to, gas chromatography, liquid chromatography, matrix assisted laser desorption/ionization, capillary electrophoresis, mass spectrometry, ultraviolet-visible spectroscopy, and flame ionization detection. This review aims to summarize the various ingredients and components of beer, discuss how they affect the finished product, and present some of the analytical methods used for quality control and understanding the formation of chemicals in beer during the brewing process.
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Affiliation(s)
- Hailee E Anderson
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX, 76019, USA
| | - Ines C Santos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX, 76019, USA; Affiliate of Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Zacariah L Hildenbrand
- Affiliate of Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, 76019, USA; Inform Environmental, LLC, 6060 N. Central Expressway, Suite 500, Dallas, TX, 75206, USA
| | - Kevin A Schug
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX, 76019, USA; Affiliate of Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, 76019, USA.
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Oehler C, Janett F, Schmitt S, Malama E, Bollwein H. Development of a flow cytometric assay to assess the bacterial count in boar semen. Theriogenology 2019; 133:125-134. [PMID: 31091483 DOI: 10.1016/j.theriogenology.2019.04.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 01/26/2023]
Abstract
The aim of the study was to develop a new flow cytometric assay for the determination of the bacterial count in commercially processed boar semen. In total 224 fresh boar semen samples collected at an AI-station were analyzed. The number of total viable counts (TVC) was determined by using flow cytometry after staining with SYBR Green I and Propidium Iodide (PI). In the first part of the study 111 fresh boar semen samples were spiked with pure cultures of defined numbers of bacteria commonly detected in boar ejaculates and analyzed by flow cytometry. In the second part, 113 fresh semen samples were assessed on the day of collection through flow cytometry and the Most Probable Number (MPN) method, as the standard bacteriological method. The first part of the study showed a strong correlation between the detected and expected numbers (r = 0.96; P < 0.001), while in the second part of the study the TVC determined by flow cytometry and by the MPN method correlated only moderately (r = 0.28; P < 0.01; median MPN: 24,000 ± MAD 21,600 bacteria/mL; median flow cytometry: 24,426 ± MAD 15,610 bacteria/mL). In summary flow cytometry is a fast alternative to the classical culture technique to determine highly contaminated boar ejaculates. The developed flow cytometric protocol enables one to enumerate the viable bacteria within fresh boar ejaculates without requiring numerous treatment steps, and thus offering the possibility of an on-line use in AI-centers.
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Affiliation(s)
- Christin Oehler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
| | - Fredi Janett
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sarah Schmitt
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Eleni Malama
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Heinrich Bollwein
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Wang H, Zhang X, Wang G, Jia K, Xu X, Zhou G. Bacterial Community and Spoilage Profiles Shift in Response to Packaging in Yellow-Feather Broiler, a Highly Popular Meat in Asia. Front Microbiol 2017; 8:2588. [PMID: 29312261 PMCID: PMC5743932 DOI: 10.3389/fmicb.2017.02588] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 12/12/2017] [Indexed: 11/27/2022] Open
Abstract
The consumption of yellow-feathered broiler has been advocated for purchasing with chilled meat rather than live broilers in Asia due to the outbreaks of animal influenza. Here, the microbial community of chilled yellow-feathered broiler response to modified-air packaging (MAP, 80% CO2/20% N2) and penetrated-air packaging (PAP, air-filling) during storage was revealed by a combination of whole-metagenome shotgun sequencing and traditional isolation methods, and the volatile organic compounds and proteolytic activity of representative dominant isolates were also accessed. The results revealed that MAP prolonged shelf life from 4 to 8 days compared to PAP, when the numbers of total viable counts and lactic acid bacteria reached more than 7 log CFU/g. Aeromonas, Acinetobacter, Escherichia, and Streptococcus occupied the bacteria communities in initial broiler carcasses. MAP dramatically increased the bacteria diversity during storage compared to PAP. Clear shifts of the dominant bacteria species were obviously observed, with the top genera of Aeromonas, Lactococcus, Serratia, and Shewanella in MAP, whereas the microbial communities in PAP were largely dominated by Pseudomonas. The isolates of Pseudomonas from PAP carcasses and Aeromonas from MAP carcasses displayed strong proteolytic activities. Meanwhile, the principal component analysis based on the volatile organic compounds indicated that the metabolic profiles greatly varied between each treatment, and no link between the natural odor of spoilage meat in situ and the volatile odor of the dominant isolates incubated in standard culture was found. These data could lead to new insights into the bacteria communities of yellow-feathered broiler meat during storage and would benefit the development of novel preservative approaches.
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Affiliation(s)
- Huhu Wang
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Xinxiao Zhang
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Guangyu Wang
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Kun Jia
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Xinglian Xu
- National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
| | - Guanghong Zhou
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China
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